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Remote sensing uncertainty in GIS

5 April 2013 - 7:51am
The article of G. G. Wilkinson is dated, and this is significant in a field that is rapidly evolving. Nonetheless, in my point of view, the author’s argument is still valid today. He talks about uncertainty and data structures in remote sensing and GIS. Sophisticated technologies and remote sensing don’t automatically solve the problem of [...]

Certainty of Uncertainty!

4 April 2013 - 10:42pm
Helen Couclelis wrote an article called Certainty of Uncertainty and I think that David J. Unwin is making a similar point. The problem of uncertainty is not merely technical. Uncertainty doesn’t only come from data and information but it is also about geographical knowledge that is sometimes inevitably uncertain. There are things that we simply [...]

Uncertainty

4 April 2013 - 9:23pm
Uncertainty lies at the core of GISci where MacEachren et al. acknowledges the GISci community has given more attention to formalizing approaches to uncertainty than in other communities such as information visualization communities (p. 144). The authors go through several examples of how uncertainty can be visualized from changes in hue to symbols with different [...]

Integrating RS and GIS

4 April 2013 - 6:12pm
Brivio et al. provides a case study where the integration of GIS and RS is able to compensate for limitations that may exist in each technology. The study provides a good example of how these two closely related fields can combine together to produce a more realistic representation of various phenomenon. While this case study [...]

Visualizing uncertainty

4 April 2013 - 6:00pm
MacEachren et als article provides a thorough overview of the current status of uncertainty visualization along with its future and its challenges. It seems to be established that uncertainty visualization is more useful at the planning stage than at the user stage of an application. This makes me think back to an earlier discussion on [...]

Are We Certain that Uncertainty is the Problem?

4 April 2013 - 4:44pm
Unwin‘s 1995 paper on uncertainty in GIS was a solid overview of some of the issues with data representation that might fly under the radar or be assumed without further comment in day-to-day analysis.  He discussed vector (or object) and raster (or field) data representations, and the underlying error inherent in the formats themselves, rather [...]

No matter how good technology becomes,

4 April 2013 - 1:53pm
No matter how good technology becomes, we will always face challenges in data uncertainty and error; the question is, can we develop appropriate techniques to mitigate the effects of these noises, and come away with the correct signal. As MacEachren et al. (2005) point out in their article titled “Visualizing Geospatial Information Uncertainty”, we use [...]

What’s the hard part now?

4 April 2013 - 1:35pm
Remote Sensing and GIS technology has changed significantly since Wilkinson (2007) wrote his review on how the two fields overlap. Hyperspectral imagery is now commonplace, and the software is well equipped to deal with it. Currently, we still struggle with handling error and uncertainty, but there are prescribed ways for dealing with each issue. Atmospheric [...]

Problems of classification

4 April 2013 - 9:07am
Since the paper by Wilkinson in 1996 many satellites have been put into orbits and several million GBs of satellite image have been collected. But more importantly, with the coming of the digital camera there has been an explosion in the amount of digital images that have been captured. Consequently, people were quick to spot [...]

GIS&RS

4 April 2013 - 1:51am
Brivio et als paper presents a case study integrating Remote Sensing and GIS to produce a flood map. After explaining methodology and results of other methods, the paper finds the integrative method to be 96% accurate. This speaks to the value of interdisciplinary work. While RS applications on their own proved inadequate, a mixing of [...]

Time or Space

4 April 2013 - 1:47am
Geospatial analysis can be no better than the original inputs, much like a computer is only as smart as its user. In the field of remote sensing, this ideology may be on its way to becoming obsolete. Brivio et. al show from a case study of catastrophic inundation in Italy that they can compensate for [...]

GIS and RS: how do we account for variability?

3 April 2013 - 11:59pm
Brivio et al.’s article “Integration of remote sensing data and GIS… for mapping of flooded areas” presents the very common process of using RS data and GIS  to map flooding and flood plains. Although the article presents how the integration of RS and GIS can accurately map a flood with a concluded method  accuracy of [...]

Visualizing Uncertainty: mis-addressed?

3 April 2013 - 10:22pm
“Visualizing Geospatial Information Uncertainty…” by  MacEachren et al. presents a good overall view of geospatial information uncertainty and how to visualize it. However that said, many parts seemed to convey that all uncertainty must be defined in order to make correct decisions. In my realm of study, although it would be nice to eliminate or [...]

Error prone GIS

1 April 2013 - 3:43am
In any data related field great efforts are put into ensuring the quality and integrity of the data being used. It has long been recognized that the quality of results can only be as good as the data itself, moreover, the quality of data is no better than the worst apple in the lot. Hence, for any [...]

geocode all the things

22 March 2013 - 12:17am
Goldberg, Wilson, and Knoblock (2007) note how geocoding match rates are much higher in urban areas than rural ones. The authors describe two routes for alleviating this problem: geocoding to a less precise level or including additional detail from other sources. However, both these routes result in a “cartographic confounded” dataset where accuracy degrees are [...]

To Digitize or Not to Digitize?

21 March 2013 - 11:27pm
No process in GIS perfect. There are always limitations, many of which can be ignored, while others must at least be acknowledged. The application of the results of an analysis can have a drastic impact on whether errors are ignored, acknowledged, or painstakingly resolved. Consider  the difference between geocoding addresses at the national level to [...]

Statutory warning: Geocoding may be prone to errors

21 March 2013 - 10:16pm
The last few years have seen tremendous growth in the usage of Spatial Data. Innumerable applications have contributed to the gathering of spatial information from the public. Application’s people use every day like Facebook and Flickr have also introduced features with which one can report their location. However, people are not generally interested in geographic [...]

Is There a Problem with “Authoritative” Geocoding?

21 March 2013 - 4:29pm
Roongpiboonsopit and Karimi provide a very interesting study on the quality of five relatively known geocoding services.  Google Maps is something I use very often, however I never really critically thought about the possible errors that may exist and their consequences.  A study such as this allows us to understand the underlying parameters that go [...]

Unloading on Geocoding

21 March 2013 - 2:58pm
Geocoding, like many of the concepts that we study in GIScience, is very dependant on the purpose of the process. The act of geocoding is often confused with address matching, which is sometimes correct, however it can also be georeferencing any geographic object and not just postal codes. This implies that the perception of geocoding [...]

Initiate the Geocoding Sequence

21 March 2013 - 2:50pm
Geocoding is the fascinating process of associating an address or place name with geographic coordinates. Traditionally, Geocoding was solely the realm of specialists, requiring a specific set of skills and equipment. However, with the advent of modern technology, including Web 2.0 applications, Geocoding is now easier than ever for the everyday user. However, despite the multitude of Geocoding services, such as [...]